Lathe for truing commutators



MALKUS O. ANKARBERG, OF FORT CLARK, NORTH DAKOTA.

LATHE FOR TRUI'NG CODIE'IUTATGRS.

Application filed August 5, 1920.

To all whom it may 00W 061% Be it known that l', MALKUs ANKAR- BERG, a citizen of the United States, residing at Fort Clark, in the county of Oliver and tate of North Dakota. have invented certain new and useful Improvements in Lathes for Truing Commutators, of which the following is a specification.

h'ly invention relates to lathe for truing connnul'ators. An object is to provide a device of this character which can be readily operated by hand. or by power if desired, and which will quickly turn down or true up commutators such as those on generators used for automobile starters. It will be obvious that the device can also be used for turning down other light metal parts.

The full objects and advantages of my invention will appear in connection with the detailed description thereof and the novel features embodied in my inventive idea will be particularly pointed out in the claims.

In the accompanying drawings;-

Fig. 1 is a top plan view. Fig. 2 is a front end view. Fig. 3 is a side elevational view with the frame shown in section on the line 33 of Fig. 1. Fig. 4 is a view in section on the line 4- 1 of Fig. 3.

Referring to the particular construction shown in the drawings, the numeral 10 designates a base member at the ends of which standards 12 and 14- extend upwardly, these standards carrying a rectangular horizontally-disposed frame having end members 16 and 18 and side members 20 and 22. The end member 16 is provided with an angular member 24;, while a dead spindle 26 is mounted in openings in the supporting and end members. The inner end of this spindle is provided with a centering point 27 and the spindle may be set in adjusted position in any suitable manner. As shown, the end member 16 is provided with a slit 28 across which bolts 30 extend so that the spindle may be clamped in proper position. The end member 18 is provided with an angular supporting member 32, while a live spindle 3 1- is mounted in openings in these supporting and end members. The inner end of the spindle 34 is provided with a centering point 35, while a gear 36 positioned between the support 32 and the end member 18 is secured to the spindle 34- by a set-screw. Meshing with the gear 36 is a gear 38 which is secured to a short shaft 40 supported in Specification of Letters Patent.

Serial No. 401,349.

the standard A and in an arm 12 depending from the support The shaft 4-0 is provided with means for turning the same such as a crank handle llileshing with the gear 38 is a gear 46 secured to a short shaft 48 mounted in bracket members f? and 49 on the standard 14. and on the arm 42 re" spectively. Secured to the shaft 48 is a small gear 50 which meshes with a large gear 52 secured to the end of a feed rod 54L passing through the standard 14: and the arm 4-2 and held in place by a collar 56 engaging the arm 4-2. The threaded portion of the feed rod 54- passes through a nut 58 secured to a support 60 which i mounted for sliding movement by means of a flange 62 011 its lower end which engages the base member 10. the support 60 also engaging the side of a longitudinal bar 64: extending between the standards 12 and 14:. A cutter 66 has a shank portion provided with aslot 68 through which the feed rod 54: extends. and the cutter is held in desired adjusted position by a set-screw 70 passing through a portion of the support. The drawings show an armature A. and commutator (l mounted on the centering point 27 and 35. In order to turn the armature and commutator the shaft thereof may be provided with a bent arm 72 which engages a pin 74: secured to the spindle 34.

he operation and advantages of my invention will be readily understood from the foregoing description. The device can be held in a vise by placing the base 10 in the jaws thereof or the device can be clamped to any suitable support. \Vhen a commutator is to be trued the armature shaft is positioned between the spindles 26 and 34k and the cutter 66 is set to cut the proper amount from the commutator. Upon turning the shaft 40 by the crank handle 14;, or by power if desired, the commutator will be rotated in contact with the cutter 66. The feed rod 54 on account of the reduced gearing by which it is operated will be rotated at a less rate of speed and the cutter 66 will move along the commutator and bring the segment thereof to a uniform circumferential surface. reversing the direction of the shaft 40 it is obvious that the cutter may be moved back and forth along the rotating commutator.

I claim: 1. A lathe for truing commutators comprising a base member, standards extending upwardly from the ends of said base mcmher, a rectangular frame carried by the upper ends of said standards, an adjustable centering spindle mounted in the rear end of said frame, a rotatable centering spindle mounted in the front end of said frame, means associated with said rotatable spindle forcausing rotation of an article held between said spindles, means for rotating said rotatable spindle, a screw-threaded feed rod, means for rotating said feed rod at a reduced rate of speed, a support mounted for sliding movement on said base member, ,a nut on said support with which said feed rod engages, and a cutter adjustably carried by said support.

2. A lathe for turning commutators comprising a base member, standards extending upwardly from the ends of said base member, a rectangular frame carried by the upper ends of said standards, an adjustable centering spindle mounted in the rear end of said frame, a rotatable centering spindle mounted in the front end ofsaid frame, means associated with said rotatable spindle for causing rotation of an article held between said spindles, a gear secured to said rotatable spindle, an arm depending from said frame and spaced from the front standard, a power-shaft rotatably mounted in said standard and said arm, a gear secured to'said shaft and meshing with said first mentioned gear, a screw-threaded feed rod rotatably mounted in said front standard and said arm, means for rotating said feed rod at a reduced rate of speed from said power shaft, a support mounted for sliding 'movement on said base member, a nut on said support with whichsaid feed rod engages, and a cutter adjustably carried by said support.

3. A lathe for truing commutators comprising a base member, standards extending upwardly from the ends of said base member, a rectangular frame carried by the upper ends of said standards, an adjustable centering spindle mounted in the rear end of said frame, a rotatable centering spindle mounted in the front end of said frame, means associated with said rotatable spindle for causing rotation of an article held between said spindles, a gear secured to said rotatable spindle, an arm depending from said frame and spaced from the front standard, a power shaft rotatably mounted in said standard and said arm, a gear secured to said shaft and meshing with said firstmentioned gear, bracket members extending from said standard and said arm, a shaft rotatably mounted in said bracket members, a gear secured to said last-mentioned shaft and meshing with said second-mentioned gear, a smaller gear also secured to said lastinentioned shaft, a screw-threaded feed rod rotatably mounted in said front standard and said arm, a large gear secured tosaid feed rod and meshing with said smaller gear, a support mounted for sliding movement on said base member, a nut on said support with which said feed rod engages, and cutter adjustably carried by said support. V

In testimony whereof I hereunto affix my signature.

M ALKUS O. ANKARBERG. 

